Gas engineer or sparky?

happybiker

pinkteapot wrote: »

We do want to change the functionality. At present, we can either have "hot water only" or "central heating and hot water". There is no option to have the heating on without the hot water. As we have electric showers, we use very little hot water so last winter we were heating the water far more than necessary. We'd like a programmer that will do central heating only.

To change functionality might mean altering pipework and putting extra controls on the system. What you have is normal for most installations and to gain the 'Heating only' advantage could be very expensive to achieve. Just a programmer change will probably not give you what you want.

pinkteapot

OK. The existing programmer is a rather retro looking Honeywell ST7000.

Pic: http://www.flickr.com/photos/55127243@N04/6354732567/in/photostream

Only the user guide is online - http://www.honeywelluk.com/Documents/All/pdf/1033.pdf

I have a hard copy of the installer guide (which includes wiring inside the box) but I can't find it online.

Re the last comment, a programmer like the one below has separate timing for heating and water.
http://www.honeywelluk.com/Products/Time-Controls/Wired/ST699/

Does this mean that installing one like this simply won't work with our boiler? Who do we ask for advice on which programmer will work with the boiler - I assume that if we were changing the boiler then the gas engineer would advise on what system to get and a sparky would just do any wiring required...

keystone

pinkteapot wrote: »

OK. The existing programmer is a rather retro looking Honeywell ST7000.

which works from mains so now you are truly confusing this poor little bunny. It has a back up battery though.

Cheers

shaun_from_Africa

Does this mean that installing one like this simply won't work with our boiler? Who do we ask for advice on which programmer will work with the boiler

To get the hot water/heating/heating + hot water option, it's not the boiler that would need changing but the control valve.

This is a unit that determines where the output flow from the boiler is directed and is usually located close to where your pump is fitted.
Normally (but not always) it is in the roof of the property at or near the highest point of the system so if it does need replacing then it can often be carried out without draining down the entire system.

A 3 way motorised valve will cost you round about £70 to £90 + fitting.

happybiker

pinkteapot wrote: »

OK.

Re the last comment, a programmer like the one below has separate timing for heating and water.
http://www.honeywelluk.com/Products/Time-Controls/Wired/ST699/

Does this mean that installing one like this simply won't work with our boiler? Who do we ask for advice on which programmer will work with the boiler -

From another 'Confused little bunny'
Correct, I would be very surprised if your current system is capable of allowing independant control of the heating alone. I would suggest that you just change for an equivilent as altering the system to comply with part L1 of the building regulations could be expensive. If you wish to cut your running costs for a reasonable outlay, have you considered insulating any bare copper pipework and increasing the insulation on your hot water cylinder, the better the insulation, the less the boiler will have to cycle to keep the hot water topped up.

Any programmer capable of dealing with gravity hot water and pumped heating will do, that means the majority of programmers on the market now.Any central heating engineer will be able to advise you, most will do their own wiring if replacing the system. As you have basic water/ heating control now, I presume you have the ST7000A as there are several versions. Wiring is 240v mains and the connections are L,N,E clearly marked on the backplate with the boiler wired into connection no.3 and the Room stat/pump wire for the heating into no.4. One of the simplest programmers to wire up ever produced.

The ST699 programmer that you have provided a link to will work on your system with a little wiring alteration that can be done by any competant person. A sparky would be ideal. You will only be able to use it in the same way as your old one works though. I doubt the system will support separate central heating control

pinkteapot

Just to throw some more confusion into the mix:

1) It's not the ST7000A. It is not mains powered. The only wire into the back of it is the one from the boiler. It is powered only by the 2 AA batteries*.

2) We have a three way valve in the airing cupboard. It's old and doesn't work brilliantly as when we're on HW only the upstairs radiators get slightly warm.

3) My brother is a plumber (bathrooms, limited heating experience so can't really help) and he said it's not a gravity hot water / pumped system. Although when I asked what type of system we had he said "just an ordinary gravity one". Not sure if this does mean gravity hot water and he didn't realise that. I have read that if you have gravity hot water or pumped then you can't have separate CH timing.

There is a friendly GasSafe registered guy round the corner - had him round last year to service our ancient gas fire that looked like it hadn't been used in years (you can spot a theme with our heating equipment!). Might have to give him a call and see if he can advise on programmers as I'm just thoroughly confused now. Screwfix catalogue talks about the number of channels and number of wires and I have no clue what we need.

Also, most seem to have separate CH/HW time settings (unlike ours). I did notice that in the Honeywell ST699 installer guide it says that it can be installed on gravity hot water / pumped systems but the separate CH timing won't work. It's supplied with a "CH + HW" sticker that the installer is meant to stick over the bit that says "CH". High tech. BTW, I'm not that fussed if we don't end up with separate CH timing - just a nice-to-have.

As I said, going to be a pain as there's no mains power to the site where the programmer is, as it's battery powered. It's right under the boiler though so maybe whoever ends up doing the job can spur a power line off of the boiler power without making too much of a mess. It's also above the dishwasher so there's plenty of power in the general area.

Thanks for all the attempts to help and apologies for all the confusion I've caused!

* From the instruction book:

"When the batteries run too low to operate the ST7000, the display will fade and the Central Heating System will not work. Change the batteries by sliding the bottom tray out sideways. Fit two new AA size LR6-1 1.5 volt alkaline batteries into the tray and slide it into place. When the new batteries are fitted, the clock will be at 12:00pm (noon) and the built-in programme will be re-established. Set the clock to the correct time and adjust the programme as required.

Mains Power Failure - If the mains supply fails, there will be no heating because there will be no electricity to run the boiler and pump. However, the timer will still operate since it is battery powered and the programme will not be lost."

Canucklehead

Hi.

The instructions are a little ambiguous, it suggests that it is battery powered but is only the time and programme memory that it maintains.

Have you actually taken the programmer off the base plate and seen whats behind? You will most likely find L.N.E. chased in the wall to the base plate.

You have an open vented fully pumped system, with (as you say) a three port valve.

These can be wired to give independant c/h and h/w.

Some sparks will have no idea how these things are wired, some do.

Ask whoever you choose to get in if they are familiar with heating wiring.

The fused switch/ plug/whatever, electrical supply to the system, must be fused at 3 amps.

GSR

PS.

The three port might have some dirt in it giving partial circulation to upstairs.

It could also be reverse circulation due to the pipework installation. A decent installer will be able to tell.

Don't get ripped off though:)

happybiker

pinkteapot wrote: »

Just to throw some more confusion into the mix:

1) It's not the ST7000A. It is not mains powered. The only wire into the back of it is the one from the boiler. It is powered only by the 2 AA batteries*.

2) We have a three way valve in the airing cupboard. It's old and doesn't work brilliantly as when we're on HW only the upstairs radiators get slightly warm.

3) My brother is a plumber (bathrooms, limited heating experience so can't really help) and he said it's not a gravity hot water / pumped system. Although when I asked what type of system we had he said "just an ordinary gravity one". Not sure if this does mean gravity hot water and he didn't realise that. I have read that if you have gravity hot water or pumped then you can't have separate CH timing.

There is a friendly GasSafe registered guy round the corner - had him round last year to service our ancient gas fire that looked like it hadn't been used in years (you can spot a theme with our heating equipment!). Might have to give him a call and see if he can advise on programmers as I'm just thoroughly confused now. Screwfix catalogue talks about the number of channels and number of wires and I have no clue what we need.

aHHHHHHHHH, that information puts us into a whole new ballgame.

All the ST7000 programmers are mains powered to my knowledge. Fully pumped is good for what you want to achieve. Are there any part numbers on the Motorised valve? is it a white plastic top or grey metal? Do you have a room thermostat, if so what model? That would enable us to determine what system you have now and the best way to tackle your problem.

Possibly you could just update the Motorised valves and controls to something like a Honeywell smartfit y plan . Your brother could do a swap on the 3 way valve and your sparky could do the wiring. The more information you can give, the more we can advise

GASSAFE Registered actually means the person has passed a course on gas safety and legislation. It does not mean that they have knowledge of appliances or systems. Some do some don't. ( I was a D32/33 assessor under the Corgi scheme ) the modules haven't changed a lot since then.

pinkteapot

Thanks both - at the weekend I will give a full system description with photos. The 3-way is a grey metal box in the airing cupboard in the upstairs hall (with the hot water cylinder). Room thermostat (we only have one) is in the lounge - will have a look for make/model reference on it. We don't have TRVs or anything - just good old fashioned radiators with standard valves. House was built in 1990, no idea what, if anything, has been updated since then (previous owners didn't replace the boiler - that's all we know).

I understand re GasSafe. My brother did the course 2 years ago and was working with experienced plumbers at the time. Unfortunately their business dried up before they could sign off on enough of his boiler work for him to become registered. £3k on the course down the drain. He's been working on his own since doing bathrooms and tiling. He has said before that he could change the 3-way valve for us if need be (he also commented yesterday that Honeywell sell packs with the valve and programmer in among other things). Sparky mate is experienced and does all our electrical jobs. Can't advise on boiler programmer selection though. And if he doesn't know about the wiring of programmers we'll see if he knows anyone who does before hitting they yellow pages.

Thanks again for the ongoing help.

pinkteapot

One other quick question on a related note. I mentioned that we fully expect to have to change the boiler at some point. I mentioned on a thread re radiator balancing that I have trouble with our radiators. If they're all on (open valves), some of the downstairs ones don't get hot and the upstairs is much warmer than the downstairs. To get water into all the downstairs radiators, I have to turn off several upstairs. Then we have some cold bedrooms. It seems that there's not enough hot water in the heating to blast round all the radiators simultaneously.

If we change the boiler in the future, will this change? Is it a function of the power of the boiler? Would love a warmer house in winter. What I'm getting at is can I use the knackered programmer as an excuse with MrTeapot for changing the boiler?